Internal combustion engines include crankcases having a plurality of cylinders. The cylinders contain pistons whose reciprocating motion due to combustion events may be transferred through a crankshaft to yield a torque output of the engine. Often, engine crankcases are made of cast metal, and include passages integrally formed therein for the transfer of various fluids from one location of the engine to another. Fluids typically transferred through passages in an engine include coolant, air, fuel, oil, and so forth.
One known method of transferring fluid through an engine component, such as a crankcase, includes casting-in passages and/or drilling through material of the casting to create passages. In some engines, these passages may need to span an entire length of the engine, and the fluid they may carry during operation of the engine may be distributed to many other engine components.
Any method used to create passages in an engine component for the transfer of fluid may have design limitations associated therewith. For example, cast-in passages are advantageous in that they may be formed concurrently with a casting operation of the engine component, but are limited in their location and size because they are formed by the same mold that is used to form the engine component itself. In the case of a crankcase, passages cast in the crankcase may contain debris after the casting operation is complete, and are thus limited to locations that are capable of being cleaned, especially if these passages are used for critical fluid transfer, for example fuel or oil.
Similarly, drilled passages are advantageous in that they may be easily cleaned after a drilling operation, but they are disadvantageously time consuming and relatively expensive to create because they require a dedicated machining operation. Moreover, in the case when passages intersect within the engine component, a drilling operation used to create these passages may become even more complicated and time consuming.
Accordingly, there is a need for an improved fluid passage configuration for transferring fluid in an engine that includes intersecting passages and that is not complicated and time consuming to implement.